<!DOCTYPE HTML>
<html>
<head>
  <meta charset="utf-8">
  <title>Test for style change hint optimizations</title>
  <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
  <script type="application/javascript">

  SimpleTest.waitForExplicitFinish();

  function runTests() {

    /** Test for Bug 1251075 **/
    function test_bug1251075_div(id) {
      var utils = SpecialPowers.DOMWindowUtils;

      var div = document.getElementById(id);
      div.style.display = "";

      var description = div.style.cssText;

      div.firstElementChild.offsetTop;
      var constructedBefore = utils.framesConstructed;

      div.style.transform = "translateX(10px)";
      div.firstElementChild.offsetTop;
      is(utils.framesConstructed, constructedBefore,
         "adding a transform style to an element with " + description +
         " should not cause frame reconstruction even when the element " +
         "has absolutely positioned descendants");

      div.style.display = "none";
    }

    test_bug1251075_div("bug1251075_a");
    test_bug1251075_div("bug1251075_b");


    SimpleTest.finish();
  }

  </script>
</head>
<body onload="runTests()">
<div id="bug1251075_a" style="will-change: transform; display:none">
  <div style="position: absolute; top: 0; left: 0;"></div>
  <div style="position: fixed; top: 0; left: 0;"></div>
</div>
<div id="bug1251075_b" style="filter: blur(3px); display:none">
  <div style="position: absolute; top: 0; left: 0;"></div>
  <div style="position: fixed; top: 0; left: 0;"></div>
</div>
<pre id="test">
</pre>
</body>
</html>
